Beiträge von marcel_at_work

package de.autoDesk.activity;
 
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 
 import android.content.Context;
 import android.database.SQLException;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteException;
 import android.database.sqlite.SQLiteOpenHelper;
 
 public class DataBaseHelper extends SQLiteOpenHelper{
  
     //The Android's default system path of your application database.
     private static String DB_PATH = "/data/data/de.autoDesk.activity/databases/";
  
     private static String DB_NAME = "autoDesk.sqlite";
  
     private SQLiteDatabase myDataBase; 
  
     private final Context myContext;
  
     /**
      * Constructor
      * Takes and keeps a reference of the passed context in order to access to the application assets and resources.
      * @param context
      */
     public DataBaseHelper(Context context) {
  
         super(context, DB_NAME, null, 1);
         this.myContext = context;
     }    
  
   /**
      * Creates a empty database on the system and rewrites it with your own database.
      * */
     public void createDataBase() throws IOException{
  
         boolean dbExist = checkDataBase();
  
         if(dbExist){
             //do nothing - database already exist
         }else{
  
             //By calling this method and empty database will be created into the default system path
                //of your application so we are gonna be able to overwrite that database with our database.
             this.getReadableDatabase();
  
             try {
  
                 copyDataBase();
  
             } catch (IOException e) {
  
                 throw new Error("Error copying database");
  
             }
         }
  
     }
  
     /**
      * Check if the database already exist to avoid re-copying the file each time you open the application.
      * @return true if it exists, false if it doesn't
      */
     private boolean checkDataBase(){
  
         SQLiteDatabase checkDB = null;
  
         try{
             String myPath = DB_PATH + DB_NAME;
             checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
  
         }catch(SQLiteException e){
  
             //database does't exist yet.
  
         }
  
         if(checkDB != null){
  
             checkDB.close();
  
         }
  
         return checkDB != null ? true : false;
     }
  
     /**
      * Copies your database from your local assets-folder to the just created empty database in the
      * system folder, from where it can be accessed and handled.
      * This is done by transfering bytestream.
      * */
     private void copyDataBase() throws IOException{
  
         //Open your local db as the input stream
         InputStream myInput = myContext.getAssets().open(DB_NAME);
  
         // Path to the just created empty db
         String outFileName = DB_PATH + DB_NAME;
  
         //Open the empty db as the output stream
         OutputStream myOutput = new FileOutputStream(outFileName);
  
         //transfer bytes from the inputfile to the outputfile
         byte[] buffer = new byte[1024];
         int length;
         while ((length = myInput.read(buffer))>0){
             myOutput.write(buffer, 0, length);
         }
  
         //Close the streams
         myOutput.flush();
         myOutput.close();
         myInput.close();
  
     }
  
     public void openDataBase() throws SQLException{
  
         //Open the database
         String myPath = DB_PATH + DB_NAME;
         myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
  
     }
  
     @Override
     public synchronized void close() {
  
             if(myDataBase != null)
                 myDataBase.close();
  
             super.close();
  
     }
  
     @Override
     public void onCreate(SQLiteDatabase db) {
  
     }
  
     @Override
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
  
     }
  
         // Add your public helper methods to access and get content from the database.
        // You could return cursors by doing "return myDataBase.query(....)" so it'd be easy
        // to you to create adapters for your views.
  
 }